More and more applications of LCDsxe2x80x94for example for use in automobiles, in which a temperature range from xe2x88x9240 to 100xc2x0 C. can easily occur, but also for portable devices such as mobile telephones and notebook PCs, require liquid-crystal mixtures which have a very broad operating temperature range, but also a very low threshold voltage.
There is thus a continuing demand for novel, suitable liquid-crystal mixtures and liquid-crystal mixture components. As described by Ichinose et al. (IDW""00, Abstr. LCT4-3) or in DE-A-100 50 071, materials are sought which combine high optical anisotropy (xcex94n) and low rotational viscosity, with other parameters also being required, such as high absolute values of dielectric anisotropy (xcex94n) in addition to further application-relevant parameters.
It is therefore the object of the present invention to provide novel components for use in nematic or cholesteric or chiral smectic liquid-crystal mixtures which have high absolute values of dielectric anisotropy combined with a favorable viscosity/clearing point ratio. Moreover, the compounds should have a high light and UV stability and thermal stability. They should furthermore be suitable for realizing high voltage holding ratios (VHR). They should also be readily obtainable synthetically and thus potentially inexpensive.